You don't "need" a teacher. There are many articles and resources on this website and many other websites at hand. Look for e-books,magick blogs,videos,ect. Use common sense to fish out misinformation and to discredit a source. Then....that's all the teachers you should need.

Join an online coven if you need extra help. You won't have much luck finding a teaching since those wise enough to teach don't for a few reasons, one being it's illegal to teach a minor without parental permission in most places, and two because magic is something you need to feel and be face to face with. It's like describing heat, sure, it can be done, but if you don't feel it, you'll never fully understand. Most people read books and watch videos and practice what they read.